Integrated phosphoproteome and transcriptome analysis reveals Chlamydia-induced epithelial-to-mesenchymal transition in host cells

Chlamydia trachomatis are the etiological agents of a range of diseases and are epidemiologically associated with cervical and ovarian cancers. The interplay between host and chlamydia is highly complex, and to obtain panoramic view of the functional interplay, we performed combinatorial global phosphoproteomic and transcriptomic analyses of C. trachomatis-induced signaling. We identified numerous previously unknown C. trachomatis phosphoproteins and C. trachomatis-regulated host phosphoproteins that are substrates of kinases involved in various cellular processes. Interestingly, several host transcription factors (TFs) that are phosphorylated in C. trachomatis infections, including ETS2 repressor factor (ERF), proto-oncogenic transcription factor ETS1 are targets of ERK MAPK signaling. While these TFs were found to be essential for Chlamydia development, we demonstrated their involvement in inducing epithelial-to-mesenchymal transition in C. trachomatis infected cells by transcriptional regulation of genes involved in cellular motility and invasion. Our data reveals substantially unexplored complexity of C. trachomatis-induced signaling and provides broader insights into pro-carcinogenic potential of C. trachomatis.